1. Field of the Invention
The invention relates to a method and apparatus for the mechanised production of knotted dough products, in particular pretzels made from dough strands. U.S. application Ser. No. 10/585,521, filed Jul. 7, 2006, and the other specifically enumerated parent applications from which priority is claimed above, are hereby incorporated herein by reference.
2. Description of the Related Art
The automatic manufacture of knotted dough products, in particular pretzels, is a huge technical challenge, since the tying of the dough strands is a very complex operation for manufacturing technology. Various attachments for automated pretzel manufacture are known from the prior art, as follows:
The patent specification DE 3841395 C1 from the Oswald Piller bakery describes a method and apparatus for manufacturing pretzels. As a starting product in the disclosed method or in the disclosed apparatus, a dough strand is used, which is grasped at its ends by suction cups. In a further step, the suction cups are raised with the dough strand ends and are displaced in the horizontal direction in such a manner that the dough strand middle portion is laid around a fixed stop. In further steps, the dough strand ends are tied together by rotation of the suction cups about a common axis and are deposited on the dough strand middle portion.
The following applications by the same Applicant suggested another method and have replaced the horizontal motion of the suction cups or other gripper devices with a horizontal motion of the stop around which the middle portion of the dough strand is laid. In this connection, we refer to printed specifications DE 4336329 C1, DE 4441301 C1 or also DE 19511409 C1.
The printed specification EP 1255441 B1 by the Applicant of the present patent application also describes a method and apparatus for manufacturing pretzels. In the disclosed manufacturing process, a dough strand curved in a U-shape is moved over a shaping table by means of conveyor belts. Through the shaping table, semi-circularly arranged holding pins engage, which together with the shaping table form a stop for the dough strand middle portion. In a first step the dough strand is moved against the stop by means of the conveyor belts and the dough strand ends are grasped at the end of the shaping table by gripper devices. In a second step, the dough strand is stretched by a specified degree of stretch in that the stop, in particular the holding pins, are displaced counter to the original conveying direction of the dough strand, the gripper devices holding the dough strand ends remaining stationary. In further steps, the gripper devices are moved into a tying position for tying of the dough strand ends and thereafter into a depositing position for depositing the dough strand ends on the dough strand middle portion.
The object of the invention is to create a method and apparatus of the type mentioned in the introduction which permit a structurally simplified, economical mechanised manufacture of knotted dough products with a reduced number of drive components.